Posted 31 August

On 11 August 2026 we had a multi-hour night-time AC power loss at our home, and although I was able to get our backup power generator running and AC power partially restored, there were some ‘issues’.

When our house was built in 2000, I had the electrician install a 240-volt twist-lock receptacle in the garage and an auxiliary breaker panel at the main AC breaker location to support the use of a backup AC power generator. Then I fabricated a 50′ jumper cable so the generator could be connected to the 240-volt connector while still outside the garage.

I didn’t actually buy the generator shown below until 2022, as AC power in our area has been very reliable, and other than testing the unit and transfer switch, it was never used ‘in anger’ until a couple of weeks ago when we had a night-time multi-hour power interruption.

I have a hobbyist engineering lab in our home, with several PC’s protected from short AC interruptions with typical single-PC UPS units. So, when the power loss occurred all the lights went out, but our PCs (and their associated displays) stayed up so we weren’t totally in the dark, but I knew that wasn’t going to last long – I needed to get that generator going before we were totally in the dark.

Using my phone as a flashlight (VERY helpful!) I went out into the garage, where I was immediately faced with the problem of getting the garage door open with no AC power. After finally getting the door open, I got the generator moved outside and tried to start it up – no dice; the electric starter solenoid just chattered without actually engaging the motor. A quick visual inspection showed that the onboard 12V SLA batter was grossly swollen – most likely due to my use of an old-style battery charger to keep the battery topped off. Fortunately, I was able to get the generator started using the manual pull cord – yay!

After getting the generator started, I got the 50′ extension cable connected to the 240-volt power receptacle in the garage and toggled the transfer switch on the emergency power sub-panel in the utility room, again using my phone as a flashlight. After toggling the transfer switch, I got lights and PC power back in my engineering lab, but there were still some issues.

• Both the in-house refrigerator and the freezer in the garage were still unpowered (this was later found to be due to me finger-fumbling the transfer switch)
• The house internet router and LAN ethernet switches were still unpowered. This was unexpected, but not a big deal as I was able to run an extension cord from my engineering lab space to the router/switch power strip.
• The garage door was still unpowered.

Utility power was restored after about 3 hours, so I was able to shut down the generator, toggle the transfer switch back to the default position, and generally put everything back together before going to bed. Overall an exciting evening.

31 August Update:

The next day I was able to review the previous night’s activities and make some adjustments for the next time. I ordered a new battery for the generator, and a new modern SLA-compatible float charger, as shown below:

Interestingly, I couldn’t find a replacement battery with the same terminal arrangement as the one that came with the generator. The original had the positive terminal on the left, and all compatible offerings from Amazon had the positive terminal on the right. Fortunately I was able to confirm that the attachment cables had enough slack to reach.

After getting the battery replaced and charged, I went through the entire process again – getting the garage door open, getting the generator outside the garage and started up, getting the 240-volt cable connected to the garage 240-volt receptacle, and toggling the transfer switch on the emergency power panel. This time both the house refrigerator and the in-garage freezer had power, and I realized that I had fumble-fingered the transfer switch during the actual power failure.